Lance Armstrong & His Hot Tub Kids

Lance Armstrong and his four children took a dip in the hot tub and shared this great picture on Twitter. Baby Max looks so cute in there with all the big kids! The caption read, "Kickin' it in the hottub with my fam."

The professional athlete and cancer survivor - who just turned 38 on Friday - is pictured here with his 9 1/2-year-old son Luke, 7 1/2-year-old twin daughters Isabelle and Grace, and 3-month-old son Max.

Lance and ex-wife Kristin Richard are parents to Luke, Isabelle and Grace. Anna Hansen, Lance's girlfriend, is mom to baby Max.